Rotary furnace or forge



Oct. 17, 1961 B. K. WALPOLE EI'AL 3,004,754

ROTARY FURNACE 0R FORGE Filed Jan. 14, 1959 3 Sheets-Sheet 1 gj 45 I INVENTORS Beyer/y K. Waao/e Jaak fZz'She r ATTORNEYS.

Oct. 17, 1961 Filed Jan. 14, 1959 B. K. WALPOLE EAL 3,004,754

ROTARY FURNACE OR FORGE 3 Sheets-Sheet 2 INVENTORS B ever/y A. W /e Jae/r Fisher ATTORNEYS.

Oct. 17, 1961 B. K. WALPOLE ETAL 3,004,754

ROTARY FURNACE 0R FORGE Filed Jan. 14. 1959 3 Sheets-Sheet 3 ATTORNEY 5.

U d Sta Perm Q 3,004,754 ROTARY FURNACE R FORGE,

Beverly K. Walpole, Cranston, KL, and Jack Fisher,

Taunt on,,Mass.,.assignors to National Furnace Corporation, a corporation of Rhode Island Filed Jan. 14, 1959, Ser. No. 786,852 '4 Claims. (Cl. 263-7) The invention relates to a rotary furnace or forge for heating metal work pieces to high temperatures for forgmg and/or other purposes.

A present-day practice for heating work pieces for fOlglIlg is to employ a horizontal rotating furnace or hearth which is open at one point so as to allow work to be removed or inserted in the hearth for heat treatment.

'Thehearth is of considerable extent; takes up much floor space and the relative large opening to the heating chamber allows considerable heat to escape therethrough.

An object of the present invention is to provide a rotary furnace so constructed as to heat treat work in a more efiicient way for forging and other purposes than present-day practice.

Another object of the invention is to provide a rotary furnace wherein the heat from a single heatingunit will be uniformly distributed.

Another object of the invention is to provide a rotary furnace with a flame deflecting member for uniform distribution of the flame about the work holders.

A further object of the invention is to provide a rotary furnace wherein the work will be more evenly heated by being free to tumble during the rotation of the furnace.

Another object of the invention is to provide a rotary furnace having work holders movable axially for receiving work of various lengths.

With these and other objects in view, the invention consists of certain novel features of construction as will be more fully described and particularly pointed out in the appended claims.

In the accompanying drawings:

FIGURE 1 is a side elevational view partially broken away, of a rotary furnace emboding the invention;

FIGURE 2 is a front elevational view of the furnace with part of the supporting structure omitted;

FIGURE 3 is a rear sectional view of the furnace looking as indicated on line 3-3 on FIGURE 1;

FIGURE 4 is a sectional view of the body of the furnace showing the work holders within the heating chamber of the furnace;

FIGURE 5 is a side elevational view partially in section showing an arrangement for adjustably moving the work holders; and

FIGURE 6 is a sectional view taken substantially along line 6-6 of FIGURE 5.

Referring to the drawings in more detail particularly FIG. 4, 10 designates a rotary furnace which is adapted for a variety of purposes that require work to be heated to high temperatures. The furnace is particularly adapted for heating work pieces for subsequent forging operation thereon and hereinafter will be referred to as a rotary forge in describing the same. The forge is in the form of a cylindrical body 11 having an outer cylindrical shell or wall 12 made of a heat resistance alloy, and an end or rear wall 13 made of the same material. These walls have a first thick lining of high temperature insulation material comprising cylindrical portion 14 and end portion 15. The forge is additionally lined with thick inner wall portions 16 and 17 made of high temperature refractory material. The other or front end of the forge is closed by a thick end wall 18 which is made of a castable high temperature refractory material which com pletes a work or flame chamber 19 into which projects a gas fed burner unit 20. The front end wall 18 is re- 3,004,754 Patented Oct. 17, 1961 movable and is held in position by a closure 21, see FIG- URE 1, by bolt and nut fastenings 22 engaged in lugs, 23 and 24 secured to the body 11 and closure 21 respectively. Said closure is also made of high heat resistant alloy. Thus the closure 21 and end wall 18 may be removed as occasion requires for access to the flame cham ber 19. The body of the forge rests at a rearwardly downwardly slanting position on open frame supports 25, and is suitably secured thereto be held stationary thereon. V p

A' work holder designated generally 26 comprises a circular plate or base 27, FIGURE 4, from the front side of which projects a plurality of hollow perforated cylinders or tubes forming work pockets or semi-mufl'les 28 which are equally spaced angularly with their axes at the outer marginal edge of the plate or base. A hollow cylinder 29 extends centrally from the rear side of the base 27 and is closed at the outer end by a closure plate 30. The base 27, semi-mufile 28, cylinder 29 and end closure plate 30- are all made of a high temperature heat resistant alloy. The cylinder 29 is filled with a high heat refractory block 31, which projects forwardly through the plate 27 and terminates in an enlarged conical head 32 with the apex of the cone 32 along the axial line of the gas burner 20 and against which flames from the burner may impinge and be deflected thereby about the work holder for even and uniform distribution of heat. The work holder 26 is centrally disposed within the chamber 19.

The cylinder 29 and block 31 incased thereby form a stern which extends from the base 27 within the heating chamber through an opening 33 in the rear wall of the chamber 19. The axis of the stem is concentric with the axis of body 11 so that the semi-muflles 28 extend at a slant or angle to the horizontal similar to that of the body 11. The stem 29 is rotatably supported on free rotating rollers 34 (see FIG. 3) which are mounted on bracket bearings 35 secured to the end Wall 13 of the forge or at any other suitable location. The diameter of opening 33 in the rear wall is larger than the diameter of stem 29 so as to provide clearance.. The escape 'of heat about the space between the stem and opening is blocked by a seal 36 which encircles the stem and is attached to wall 13. A heat resistant insulation soft packing 37 is carried by the seal case and engages against the stem.

A shaft 38 extends from stem 29 and is journalled in a pillow block 39 carried by uprights 40 which are secured to a carriage 41. The carriage is mounted for movement along tracks 42 which are supported on cross tie members 43 of frame 25 at the inclination or slant of the axis of this stem 29 thus the tracks extend in a plane parallel to the axis of rotation of the work holder. The carriage is moved along the tracks 42 by means of a captive screw threaded member 44 which is engaged by internally threaded blocks or nuts 45 depending from the carriage. A handle 46 is provided at the outer end of member 44 (FIG. 5) for manually turning the same in one direction or the other for moving the carriage along the tracks. Thus the work holder may be adjustably moved in chamber 19 to space the ends of muflles 28 at the required distance from the entrance opening to the chamber to be hereinafter described.

The work holder is rotated at a relatively slow speed, approximately one revolution per hour, of course this depending upon the nature of the work to be processed. This is accomplished in the present instance by means of a motor and speed reducing unit 48 of any suitable manufacture. The unit 48 is secured to the carriage 41 and the output shaft thereof carries a sprocket pinion 49 connected by a sprocket chain 50 to a sprocket wheel 51 mounted on shaft 38. Thus the power source for rotating the work holder is movable with the carriage and at the angle of slant of shaft 38.

The entrance opening 52, see FIGURE 2, into chamber 19; through which access may be had to said cham: her for the insertion or removal of work pieces inthe semi-muifles 28, is located at one side ofthe burner opening and at a distance from the center of the body substantially equal to the distance of the spacing of'muflies 28 from said center. Thus as each muffle 28 is brought into registry with said opening 52, a worker with a suitable tool, as for example tongs, may reach in the chamber and. remove work pieces from said muflie or may insert work into the mufile as the case may be; The opening 52 is of relative small size but is of; suflicient extent forthe purpose required. In order to prevent loss of heat through opening 52 inbetween times of removing or loading of the chamber, a closure 53 is pro! vided, This is slidable, mounted on guides 54 which are carried by the end closure 21. The burner 20 is fed in the known manner with a gas fuel and the flamestherefrom are directed to project or impinge on the cone 32 which deflects the same toward the, semi-muflies which protectsthe work pieces placed therein from the direct action of the flames. The flame chamber is vented in an accustomed manner by. an air curtain just inside of the operating opening to prevent the operator from being burned.

In operation the work holder 26 is adjusted to a po si tion so. as to facilitate the filling and removal of work from the semi-mufiies through opening 52, Thus for long workpieces which will project outwardly of the semi-muflles, the work holder is moved toward the rear. When the work pieces are short and are confined within the semi-muflie, the work holder is moved toward the front of the chamber 19 so as to provide for better access to the work, 7

The perforated cylinders are of a sufiicient size so that the work will roll around in the cylinders or semi-mufiles or betumbledor e piece upon another as rotation occurs. By the perforations in the cylinders or semi-mufflesand the tumbling of the work causes an even heating through the, work as the furnace is in action. The cylinders or m l lfii 1 parallel tqthe axis of rotation and thus in clined rearwardly so that the work willbe urged against the l e end h wim a a ns basal nd will not drop out of the front, end thereof.

We claim:

1. A furnace provided with a stationary substantially closed flame chamber, a rotary work holder in said chamber having .agenerally vertical base with work reeeiving tubes projecting generally horizontally from the base and spaced radially trom its axisfiof rqtationleaying anopen center between thetubes, amember carried by said base, said member being positioned. substantially along the axis of said work holder, a burner projecting into said chamber directed at said member for deflecting flames therefrom radially ,outwardly toward; .s.a id work tubes and the recirculating of heated air about said tubesr 2. A furnace provided with a stationary substantially closed flame chamber, arotary work holder said chamber having agenerally vertical, base. provided with a; pluli y of work c i g tubes rmiect n ssen ally h i zontally from the base and spaced from of rotation leaving anopen center between, said tubes, a burner nozzle projectinginto said chamben agd a conie calmember carried by said workholder. coaxial therewith, said conicalmember being positione the axial l n i burner n z l fo de cti g ..e =;.th r from radially outwardly toward saidtubes and recirculating the heated air about .saidtubes, v

. 3. A furnace as set forth in claim 2 wherein said tubes have perforated walls. 1 l

4- A rn ce asset rth n-cla m lwhe si sa tubes are inclined downwardly toward the rearthereof,

References Citediin the 0t this; patent, UNITED STA'IES. PATENTS. 

